I've been thinking about this for a while.
I think Celestia and the lost City of Atlantis are much alike.
Atlantis was an island kingdom that had advanced technology and medicine.
One day, a giant wave sank the city and buried it into the sea.
My theory is that Celestia, since its name means the stars, was once a kingdom of celestial people and objects in the Spiral.
One day a dark force(besides Malistare) flooded this world and turned the residents into sea creatures.
What do you think about this?